/***
 * ASM: a very small and fast Java bytecode manipulation framework Copyright (c) 2000-2011 INRIA,
 * France Telecom All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification, are permitted
 * provided that the following conditions are met: 1. Redistributions of source code must retain the
 * above copyright notice, this list of conditions and the following disclaimer. 2. Redistributions
 * in binary form must reproduce the above copyright notice, this list of conditions and the
 * following disclaimer in the documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the copyright holders nor the names of its contributors may be used to
 * endorse or promote products derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
 * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY
 * WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package com.googlecode.aviator.asm.commons;

import java.util.HashMap;
import java.util.Map;
import com.googlecode.aviator.asm.Type;

/**
 * A named method descriptor.
 *
 * @author Juozas Baliuka
 * @author Chris Nokleberg
 * @author Eric Bruneton
 */
public class Method {

  /**
   * The method name.
   */
  private final String name;

  /**
   * The method descriptor.
   */
  private final String desc;

  /**
   * Maps primitive Java type names to their descriptors.
   */
  private static final Map<String, String> DESCRIPTORS;

  static {
    DESCRIPTORS = new HashMap<String, String>();
    DESCRIPTORS.put("void", "V");
    DESCRIPTORS.put("byte", "B");
    DESCRIPTORS.put("char", "C");
    DESCRIPTORS.put("double", "D");
    DESCRIPTORS.put("float", "F");
    DESCRIPTORS.put("int", "I");
    DESCRIPTORS.put("long", "J");
    DESCRIPTORS.put("short", "S");
    DESCRIPTORS.put("boolean", "Z");
  }

  /**
   * Creates a new {@link Method}.
   *
   * @param name the method's name.
   * @param desc the method's descriptor.
   */
  public Method(final String name, final String desc) {
    this.name = name;
    this.desc = desc;
  }

  /**
   * Creates a new {@link Method}.
   *
   * @param name the method's name.
   * @param returnType the method's return type.
   * @param argumentTypes the method's argument types.
   */
  public Method(final String name, final Type returnType, final Type[] argumentTypes) {
    this(name, Type.getMethodDescriptor(returnType, argumentTypes));
  }

  /**
   * Creates a new {@link Method}.
   *
   * @param m a java.lang.reflect method descriptor
   * @return a {@link Method} corresponding to the given Java method declaration.
   */
  public static Method getMethod(final java.lang.reflect.Method m) {
    return new Method(m.getName(), Type.getMethodDescriptor(m));
  }

  /**
   * Creates a new {@link Method}.
   *
   * @param c a java.lang.reflect constructor descriptor
   * @return a {@link Method} corresponding to the given Java constructor declaration.
   */
  public static Method getMethod(final java.lang.reflect.Constructor<?> c) {
    return new Method("<init>", Type.getConstructorDescriptor(c));
  }

  /**
   * Returns a {@link Method} corresponding to the given Java method declaration.
   *
   * @param method a Java method declaration, without argument names, of the form "returnType name
   *        (argumentType1, ... argumentTypeN)", where the types are in plain Java (e.g. "int",
   *        "float", "java.util.List", ...). Classes of the java.lang package can be specified by
   *        their unqualified name; all other classes names must be fully qualified.
   * @return a {@link Method} corresponding to the given Java method declaration.
   * @throws IllegalArgumentException if <code>method</code> could not get parsed.
   */
  public static Method getMethod(final String method) throws IllegalArgumentException {
    return getMethod(method, false);
  }

  /**
   * Returns a {@link Method} corresponding to the given Java method declaration.
   *
   * @param method a Java method declaration, without argument names, of the form "returnType name
   *        (argumentType1, ... argumentTypeN)", where the types are in plain Java (e.g. "int",
   *        "float", "java.util.List", ...). Classes of the java.lang package may be specified by
   *        their unqualified name, depending on the defaultPackage argument; all other classes
   *        names must be fully qualified.
   * @param defaultPackage true if unqualified class names belong to the default package, or false
   *        if they correspond to java.lang classes. For instance "Object" means "Object" if this
   *        option is true, or "java.lang.Object" otherwise.
   * @return a {@link Method} corresponding to the given Java method declaration.
   * @throws IllegalArgumentException if <code>method</code> could not get parsed.
   */
  public static Method getMethod(final String method, final boolean defaultPackage)
      throws IllegalArgumentException {
    int space = method.indexOf(' ');
    int start = method.indexOf('(', space) + 1;
    int end = method.indexOf(')', start);
    if (space == -1 || start == -1 || end == -1) {
      throw new IllegalArgumentException();
    }
    String returnType = method.substring(0, space);
    String methodName = method.substring(space + 1, start - 1).trim();
    StringBuilder sb = new StringBuilder();
    sb.append('(');
    int p;
    do {
      String s;
      p = method.indexOf(',', start);
      if (p == -1) {
        s = map(method.substring(start, end).trim(), defaultPackage);
      } else {
        s = map(method.substring(start, p).trim(), defaultPackage);
        start = p + 1;
      }
      sb.append(s);
    } while (p != -1);
    sb.append(')');
    sb.append(map(returnType, defaultPackage));
    return new Method(methodName, sb.toString());
  }

  private static String map(final String type, final boolean defaultPackage) {
    if ("".equals(type)) {
      return type;
    }

    StringBuilder sb = new StringBuilder();
    int index = 0;
    while ((index = type.indexOf("[]", index) + 1) > 0) {
      sb.append('[');
    }

    String t = type.substring(0, type.length() - sb.length() * 2);
    String desc = DESCRIPTORS.get(t);
    if (desc != null) {
      sb.append(desc);
    } else {
      sb.append('L');
      if (t.indexOf('.') < 0) {
        if (!defaultPackage) {
          sb.append("java/lang/");
        }
        sb.append(t);
      } else {
        sb.append(t.replace('.', '/'));
      }
      sb.append(';');
    }
    return sb.toString();
  }

  /**
   * Returns the name of the method described by this object.
   *
   * @return the name of the method described by this object.
   */
  public String getName() {
    return this.name;
  }

  /**
   * Returns the descriptor of the method described by this object.
   *
   * @return the descriptor of the method described by this object.
   */
  public String getDescriptor() {
    return this.desc;
  }

  /**
   * Returns the return type of the method described by this object.
   *
   * @return the return type of the method described by this object.
   */
  public Type getReturnType() {
    return Type.getReturnType(this.desc);
  }

  /**
   * Returns the argument types of the method described by this object.
   *
   * @return the argument types of the method described by this object.
   */
  public Type[] getArgumentTypes() {
    return Type.getArgumentTypes(this.desc);
  }

  @Override
  public String toString() {
    return this.name + this.desc;
  }

  @Override
  public boolean equals(final Object o) {
    if (!(o instanceof Method)) {
      return false;
    }
    Method other = (Method) o;
    return this.name.equals(other.name) && this.desc.equals(other.desc);
  }

  @Override
  public int hashCode() {
    return this.name.hashCode() ^ this.desc.hashCode();
  }
}
